ionic: fill out pci error handlers

Set up the pci_error_handlers error_detected and resume to be useful in
handling AER events.  If the error detected is pci_channel_io_frozen we
set up to do an FLR at the end of the AER handling - this tends to clear
things up well enough that traffic can continue.  Else, let the AER/PCI
machinery do what is needed for the less serious errors seen.

Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>